An Optical Transport Network (OTN) is comprised of a plurality of switch nodes linked together to form a network. The OTN includes an electronic layer and an optical layer. The electronic layer and the optical layer each contain multiple sub-layers. The optical layer provides optical connections, also referred to as optical channels or lightpaths, to other layers, such as the electronic layer. The optical layer performs multiple functions, such as monitoring network performance, multiplexing wavelengths, and switching and routing wavelengths. In general, the OTN is a combination of the benefits of SONET/SDH technology and dense wavelength-division multiplexing (DWDM) technology (optics). OTN structure, architecture, and modeling are further described in the International Telecommunication Union recommendations, including ITU-T G.709, ITU-T G.872, and ITU-T G.805, which are well known in the art.
The construction and operation of switch nodes (also referred to as “nodes”) in the OTN is well known in the art. In general, the nodes of an OTN are generally provided with a control module, input interface(s) and output interface(s). The control modules of the nodes in the OTN function together to aid in the control and management of the OTN. The control modules can run a variety of protocols for conducting the control and management of the OTN. One prominent protocol is referred to in the art as Generalized Multiprotocol Label Switching (GMPLS).
Generalized Multiprotocol Label Switching (GMPLS) is a type of protocol which extends multiprotocol label switching (MPLS) to encompass network schemes based upon time-division multiplexing (e.g. SONET/SDH, PDH, G.709), wavelength multiplexing, and spatial switching (e.g. incoming port or fiber to outgoing port or fiber). Multiplexing is when two or more signals or bit streams are transferred over a common channel. Wave-division multiplexing is a type of multiplexing in which two or more optical carrier signals are multiplexed onto a single optical fiber by using different wavelengths (that is, colors) of laser light.
RSVP and RSVP-TE signaling protocols may be used with GMPLS. To set up a connection in an Optical Transport Network, nodes in the Optical Transport Network exchange messages with other nodes in the Optical Transport Network using RSVP or RSVP-TE signaling protocols. Resources required for the connection are reserved and switches inside the network are set. Information sent by signaling protocols are often in a type-length-value (TLV) format. The same protocols may also be used to take down connections in the Optical Transport Network when the connections are no longer needed.
OSPF and OSPF-TE routing and topology management protocols may also be used with GMPLS. Under OSPF protocols, typically each node in an Optical Transport Network maintains a database of the network topology and the current set of resources available, as well as the resources used to support traffic. In the event of any changes in the network, or simply periodically, the node “floods” the updated topology information to all the Optical Transport Network nodes attached to the node. Flooding is mechanism where information received by a node is forwarded to other nodes, and is used within the OSPF protocol as a way of distributing the updated topology information quickly to every node within the Optical Transport Network. The nodes use the database information to chart routes through the Optical Transport Network.
A Flexible Ethernet network (referred to herein as “FlexE”) is a type of network that is defined by a FlexE Interoperability Agreement in 2016. FlexE supports the bonding of multiple Ethernet links, which supports creating larger links out of multiple slower links in a more efficient way than traditional link aggregation described in IEEE 802.1AX (2014). FlexE also supports the sub-rating of links, which allows an operator to only use a portion of a link. FlexE also supports the channelization of links, which allows one link to carry several lower-speed or sub-rated links from different sources. Much of the FlexE's functionality is achieved by adding a time-division multiplexing calendar that interacts with the existing Ethernet 64b66b mechanism, allowing bandwidth to be allocated with 5 Gb/s granularity. The calendar is communicated along with the data.
FlexE networks can exist in isolation (i.e. without any intervening OTNs), or can be deployed as client layers of OTNs. FlexE is backwards compatible with the existing optical transport network (OTN) infrastructure. A FlexE compatible interface can be connected to node that is not aware of FlexE. When using FlexE in this manner, FlexE traffic appears to the node as if the FlexE traffic was ordinary Ethernet traffic. In the case of the FlexE network being deployed as client layers of OTNs, FlexE information tunnels through the OTN networks—that is, the FlexE network can be described as an overlay network for the OTN. From the perspective of the FlexE network, the OTN network appears transparent, and the FlexE layer network operates independent of the underlying transport network.
A node within a FlexE network may have many physical ports. A specific type of physical port, which implements signals, formats, and interfaces compliant to IEEE 802.3-2015 is referred to in the art as an “Ethernet PHY”. The physical port and the associated software or firmware can be implemented in a variety of manners depending upon the desired data rate and/or physical media, e.g., optical or electrical, used to convey the data. As the Ethernet technology developed, many Ethernet rates were standardized, e.g. 10 M, 100 M, 1 G, 10 G, 40 G, and 100 G. 100 G is the highest standard Ethernet rate available today.
FlexE is a technology that provides a generic mechanism that can be used within a network for supporting a variety of Ethernet Media Access Control (MAC) rates (e.g., 25 Gb/s, 50 Gb/s, 200 Gb/s, etc.) that may or may not correspond to any existing Ethernet PHY rate. MAC rates can be greater than any existing Ethernet PHY rate. This can be accomplished by creating a “FlexE Group” in which more than one Ethernet PHY are logically used together. MAC rates can also be less than any existing Ethernet PHY rate. This can be accomplished by using techniques known in the art as “sub-rate” and “channelization”.
As discussed above, the current standards for a FlexE network specify a calendar used for time-division multiplexing. The calendar specifies a fixed granularity of 5 Gb/s and 20 slots per 100 Gb/s of FlexE group capacity. The granularity and a number of slots is fixed for all physical ports that are configured as part of a FlexE Group.
One problem that currently exists in implementing FlexE Networks is that there is no automated methodology for setting up or provisioning label switched paths within the FlexE Network.